An air conditioner having a compressor, condenser coil and accumulator submerged in a body of water in a water tank, wherein the water is cooled by evaporative cooling when air is circulated through a mist of water sprayed into a water evaporation chamber communicating with an air inlet into the water tank and through an air manifold in the tank.
Vapor compression systems are employed in most refrigerated air conditioning systems. Cooling is accomplished by evaporation of a liquid refrigerant under reduced pressure and temperature. The refrigerant vapor enters the compressor where the temperature is elevated by mechanical compression. The vapor condenses at this pressure in a condenser coil, if sufficient heat is dissipated. The high-pressure liquid refrigerant then passes through an expansion valve where the fluid pressure is reduced. The low-pressure refrigerant enters the evaporator where it evaporates by absorbing heat from the refrigerated space, and reenters the compressor.
Most residential central air conditioning units are split systems comprising a condensing coil, a refrigerant compressor and a fan located outside the home, and an expansion valve and a refrigerant evaporator coil that is usually part of a furnace or air handler inside the home. The air handler of the furnace blows air across the evaporator coil, which cools the air. The cool air is routed through a series of air ducts into space in the home to be cooled.
The compressor, usually controlled by a thermostat, acts as a pump that moves the refrigerant from the indoor evaporator to the outdoor condenser and back to the evaporator again, causing the refrigerant to flow through the system. It draws in a low-pressure, low-temperature, refrigerant in a gaseous state and by compressing this gas, raises the pressure and temperature of the refrigerant. This high-pressure, high-temperature gas then flows to a condenser.
The condenser normally located outside the home, is a device that transfers unwanted heat out of a refrigeration system. The condenser coil is usually formed by a series or network of aluminum-finned copper tubes filled with refrigerant that removes heat from the hot, gaseous refrigerant so that the refrigerant becomes liquid again.
The evaporator coil is a series of piping connected to a furnace or air handler that blows indoor air across the evaporator coil, causing the evaporator coil to absorb heat from the air. The cooled air is then delivered to the home through ducting. The refrigerant from the evaporator coil flows through an accumulator back to the compressor where the cycle is repeated.
The cooling capacity of the air conditioner is a measure of the ability of a unit to remove heat from an enclosed space. A long felt need exists for a condensing unit that efficiently removes heat from the system under a variety of operating conditions.
There are three types of condensers: air-cooled condensers, water-cooled condensers, and evaporative condensers. Most residential systems have an air-cooled condenser.
A fan typically draws outside air across the condenser coil of an air-cooled condenser. As the refrigerant passes through the condenser coil and the cooler outside air passes across the coil, the air absorbs heat from the refrigerant which causes the refrigerant to condense from a gas to a liquid state. The high-pressure, high-temperature liquid then reaches the expansion valve. The liquid flows through a very small orifice in the expansion valve, which causes the refrigerant to expand to a low-pressure, low-temperature gas that flows to the evaporator.
In hot regions of the country, the low temperature gradient between hot ambient air moving across the condenser coil and the hot refrigerant vapor flowing through the condenser coil prevent dissipation of enough heat which causes the system to operate at less than optimum efficiency. The compressor in the inadequately cooled system draws excessive electrical current, wasting electricity and increasing the operating cost of the system. Further, the cooling capacity of the system is often inadequate to maintain the desired temperature in an enclosed space.
An evaporative condenser uses a combination of air and water for condensing the refrigerant.
U.S. Pat. No. 5,832,739 discloses an air conditioner operating on a compressor-condenser-evaporator circuit that utilizes water cooled by air flowing over an evaporative medium through which the water flows to cool a condenser coil located in a continuous serpentine channel in a sump located at the lower side of the air conditioner unit. The condenser coils include offset intertwined upright coils that provide a large heat exchange surface with water flowing in the channel to a pump intake region of the sump. A pump is provided to supply the evaporative medium with water from the pump intake region of the sump for continuous circulation through the evaporative medium and the sump channel. A water distributor system supplies water uniformly to the top area of the evaporative medium by creating a film of water that is evenly distributed across the top of the evaporative medium. A raised area of the sump provides access to the interior of the evaporative medium without the need for a water sealing arrangement and a central platform supports the refrigerant compressor, pump and other accessories above the sump channel.
Water-cooled condensers transfer heat to water which is usually circulated through a remotely located cooling tower to remove heat.
U.S. Pat. No. 2,179,632 discloses a condenser tank containing water in which a condenser coil is submerged.
U.S. Pat. No. 2,493,141 discloses a super heat removing coil, receiver tank and pre-cooling coil immersed in water in a sump. The patent states that the compressor and a prime mover may be suspended from beneath a car in a housing or casing separate from that forming the cabinet.
U.S. Pat. No. 2,696,085 discloses a hot water heater having a motor compressor unit which supplies super heated refrigerant to a coil, both being submerged in water in the hot water heater storage tank. Refrigerant from the coil is delivered through additional coils, also submerged in water in the storage tank to an expansion valve, an evaporator and back to the compressor.
U.S. Pat. No. 2,802,342 discloses a heat pump which includes a compressor mounted within a casing containing oil and the casing is immersed in water in a tank. The patent states that in operation the gaseous refrigerant from the compressor passes to the condenser, where it gives up its heat to the water in the tank, and then flows to a liquid receiver from which it passes through an expansion valve to evaporator coils.
U.S. Pat. No. 4,250,717 discloses apparatus for utilizing waste water from an ice maker to cool the motor-compressor and associated coil of condenser tubing in that system. The apparatus features a motor-compressor around which is wrapped the condenser coil. The motor-compressor and condenser coil are contained within a water tank to which is directed waste water that has been collected from the meltdown of an ice making cycle or the condensate from a refrigerant evaporator. In applications where waste water production is insufficient a valve controlled supply of fresh water can be substituted therefor or used in conjunction with the waste water to effect cooling of both the compressor and condenser coils. The waste water in the tank will rise to the level of an overflow outlet at which point water will drain out of the tank.
U.S. Pat. Nos. 6,260,373 and 6,260,374 disclose water-source heat pumps, which typically include a compressor that compresses and circulates refrigerant in series-flow through two heat exchangers and an expansion valve. One heat exchanger transfers heat between the refrigerant and an external source of ground water. The other heat exchanger transfers heat between the refrigerant and a comfort zone, such as a room or other area within a building. Often a four-way valve determines whether the heat pump heats or cools the comfort zone by selectively directing the refrigerant flow in a forward or reverse direction.
If cooling is called for, the thermostat of a water source heat pump activates the centrifugal blower and sets the reversing valve into the cooling position. High temperature refrigerant vapor is pumped from the compressor through the reversing valve to a refrigerant-to-water heat exchanger. The refrigerant vapor condenses to a liquid as it passes through the heat exchanger, giving up its heat to the circulating water loop. High pressure liquid refrigerant then passes through the expansion device into the refrigerant-to-air fin tube coil heat exchanger. As the low pressure refrigerant passes through the coil, it evaporates to become a low temperature vapor, absorbing heat from the air, which is drawn over the coil by the blower. The refrigerant then flows as a low pressure gas through the reversing valve back to the suction side of the compressor where the cycle begins again.
The prior art devices are complicated, expensive to build and operate, and use excessive electricity. An affordable method and apparatus for extracting heat from refrigerant in residential air conditioning systems, while conserving energy, is needed.
The air conditioning system disclosed herein generally comprises four main components including a compressor, a condenser, an expansion valve and an evaporator, the heat generated in the refrigerant compressor being transferred to water that in cooled by evaporative cooling.
A scroll compressor delivers coolant at high pressure and high temperature through a condenser coil, through a high pressure refrigerant supply line, and an expansion valve and an evaporator coil. Coolant at low pressure and low temperature is delivered through a refrigerant return line and a liquid accumulator to the suction inlet of the compressor.
A water pump delivers a portion of the water from the water tank through a water line to one or more sprinkler heads which spray water into an air inlet duct. A fan draws air into the inlet duct where it passes through the water dispensed from the spray heads, which results in evaporation of the water and cooling of air delivered through the inlet duct into the water tank. Air is exhausted from the water tank through an exhaust duct. The water level of water in the tank is maintained by delivering water through a float valve connected to a water supply.
The compressor, the condenser coil and the accumulator are submerged in a body of water wherein the temperature of water is controlled by evaporative cooling. It should be noted that it does not discharge cooling water into a drain.
High energy costs are compelling air conditioner manufacturers to develop more efficient systems. The air conditioning system disclosed herein does not require inordinate heat exchanger size or new compressor technology to significantly reduce energy costs. Further, the system does not require the discharge of waste water and thus conserves resources.
High energy costs are compelling air conditioner manufacturers to develop more efficient systems. The air conditioning system disclosed herein does not require inordinate heat exchanger size or new compressor technology to significantly reduce energy costs, while improving the efficiency of the system and the ability of the system to cool the comfort zone in a building. Further, the system does not require a remote cooling tower or other sources of a large volume of water. The system does not discharge waste water and thus conserves resources.